This invention relates to cast hopper tees, and more particularly, to integral one-piece cast hopper tees having smooth and uninterrupted internal transitional surfaces permitting complete and continuous flow of product therethrough, without contamination.
Large elongated hoppers or tank trailers are commonly used to transport bulk commodities such as industrial and food products from the supplier to the manufacturer, who then converts the bulk commodity into products for consumers. When the hopper or tank trailers reach the manufacturers plant, the bulk commodity is unloaded. Typically, this is done by pneumatically unloading the bulk commodity from the hopper into clean and sanitary pipe lines at the manufacturer's location. For this purpose, hopper tees are mounted to the discharge outlet of the hopper truck and transfer the bulk commodity by gravity flow or air pressure conveyor or vibration into a vertical pipe section of the hopper tee. The hopper tee vertical pipe section is connected to a transverse or horizontal pipe section allowing the outer ends thereof to be connected in the pneumatic pipeline tubing system of the manufacturer. Pneumatic conveying of the bulk commodity through the horizontal pipe section and the pipeline tubing is achieved by establishing a pressure differential in the pipeline system, as will be apparent.
Prior art hopper tees have been constructed by welding the vertical and horizontal pipe sections together, as shown for example, in the prior art drawing illustrations of this disclosure. With prior art hopper tees constructed in this manner, the welded areas of juncture leave rough and irregular internal wall surfaces, which impede the flow of the product or commodity through the hopper tee. More specifically, the welds in the area of juncture between the vertical and horizontal pipe sections of the hopper tee produce rough and irregular internal wall surfaces, which can substantially impede product flow. Also, hopper tees constructed in this manner unfortunately result in a much higher incidence of product hang up in the rough and irregular internal wall surface areas, causing product contamination. As can be appreciated, a potential problem exists with the manufacturer/user of the bulk commodity, if product hang-up, from a previous bulk commodity shipment, is released into the pipeline system of the manufacturer/user. Sometimes, abrasive dry bulk commodities such as sand result in premature wear-through of the hopper tee, in the welded areas of juncture between the vertical and horizontal pipe sections. Furthermore, an abrasive bulk commodity, as said sand, may wear-through the entire hopper tee. That is why the hopper tee, as well as the piping used for unloading, are typically made from schedule 80 heavy steel, in order to hold-up to the abrasiveness of sand, or related materials. The aforementioned problems associated with rough and costly prior art hopper tees and in conveying abrasive materials, have been overcome by the present invention, as will be made apparent in the description that is to follow.